Radio wave generator



Oct 18, 1955 M. 1. ROTHMAN ETAL 2,721,265

RADIO WAVE GENERATOR Filed Oct. 17, 1950 f /3 /M- //f f/e /7 /f/ 50 /E Y /Z "-/6 Jf7 -Lf 2 'Lf/0 29 L l 2 3 4 .i

Ja 3/2 Il Il n Il n 24) ref fa'e '75 Y army army pam' pfmv 28 NETWORK Hirn/018K Nfrwoek Erwmek 0 2/ zz z3 f/ :MIM- L NVE T0 M91. A for/Ma Rs BY e United States Patent Otiice Patented OCQ t, 2,721,5265 f "i131111,-rrespectivelyghand :theprimarywinding oftranstf 'former 11. LThec'ndense'i-s tu-1l0-discharge^morerapidly "ffRADIO-WAVEGENERATOR l 51y :than-they leifarge sineeaisehargetskespiaee'thrugh. the 1% @f f f Nj 1\/[err,`arf{--Har comparativelydowf'p'late:resistance of -the gaseous'tubes Max L Rothrgalghvlgfldtdgn N. J. ry s? whereas the-cendensers must be:chargedthroughthecomr tu par'ativelyhigh'lresistanc` of resistorsJ` 1-3-'i-17. *Appliction'ctoberA731950; Serial- 1510.- 190,630 The control grids of tubes I srrarernonuyobased g A1 Chimp `((jl250= 3,6) l't'beyontdf the eut-ufrt or-breakdown pointyfdr the Aparticular a'riodevoltageenployd; bybias potential from directrcurrent- 'bias fs'oure 18 facting through 'resistois- V19h4.31'i-The lgridcircuits ofadja'cent' tubes ii'ilthe ychairi of'tubsI-S are connected;togetherfbymeans of pulse'delay'networks 2li-L27.E Thedela'y circuits are'each radjusted topi'oduce v"-Tlieinvention"kiesfcribderein'maybe manufactured 15 tn'dused by brfdr the'Government 'forgovernm'ental pur- 'fatdelayequalftbthe'pefiod f theiadiofrequencywave to @poses -withouttpayni'ent tome ofany-royaltythereon. hf b'e-generateds Thevse'circui-ts-:niay be of "anyknownjtype S"This invntionrelates to'a 'devicefor generating radio .f-=cpable of producing therequi-reddelay suchjforexa'mple, l'frequency'energyand-particularly to* an arrangement for Fl astde'la-yhlinesg"tuhedfleicuitsrf-rriultivihratorsfQ or'phangenerating high power radio frequency Aenergy directly -3tastron"c1rcl11ts,rtheflatterbeing"a'idelayn'circuit offthegtype from an array of gaseous discharge devices. The invenl 'fdeseribed onpages-58f-64;chapter 2;" ofJ Principles of tion 'i's 'particularly'suited to the Vgeneration of pulses of 511Radarft-secondeditioni T.Radar"`cliol*StaiMchigh frequencyenergyr-such 'as-required, for example, in th GTaIw-Hill=Bol` f Company." Inputterminals-v 23x arepro- -;r,the` Loran navigational systenir-bu'tcmay also' beused to vidd'-for applying' input signal-pulses toth'efgrid of tube -ragenerateontinuous radio Waves, 1w Thefdtplltldo fr'eqll'ellCyJWaVe S`ake11lfl'Qmi0l1t- 1f Itis-accordingly an object ohtheinvention to provide Y put terminals 29 connected to the secondary( of trans- `-,.-..iniproved means for generatinghigh power radio frer'fformer11?'iiThe'seciidary'winding istuiie'd' by con- `z-ffqueneyY energy, in the form of-pulses' occurring atgregu- 0 denseif 30 tosre's'onate at theldesire'd outputv frequency.

- f-lar or irregular intervals or inthe-form of aoo'iitinuous huabovede'scfribedcircuit:operatesfluponfthe'ppliwave, which possesses a high degree of radio frequency cation of a trigger p ulse to thefinput terminals 28; .to'genstability and accuracy of time reference with respect to y @rato a pulse of highv frequency energy.-6i'ssume, for the triggering pulses. wfexample, thatlatrarn ofequallyftiine spaced'trilgger pulses,

Another object of the invention is to provide apparatus such 3S ShOWn at 31 .1n Flg. 1, are applied to input termifor generating radio frequency pulses of stable and easily nais 28. Upon application of one of these pulses to the reproducible envelope Shape grid of gaseous tube lhthis tube becomes conductive and A further object of the invention is to provide a radio allows Condenser 6, Whlehhas Previously Charged through frequency generating device which achieves a high degree reslstOf 13 t0 the POteutld 0f source' 12, t0 discharge of power conversion efliciency at high power levels. through the tube and the Pflmafy Wludlug 0f transformer An additional object of the invention is to provide high 11- The resulting Pulse 0f euefgy lldueed in the SeC- power radio frequency generating apparatus which requires 40 ondary winding 32 shock excites the resonant circuit 32- little input Signal driving power for its power output ll'ltO OSClllatlOD at ltS IeSOIlaDt frequency. AS already condition, or, in other words, which has a high power stated, the delay PlOdueed by eheh 0f hetWOrks 24-27 iS gam made exactly equal to the period of resonant circuit $2- A more Complete description of the invention be 30. 'Therefore7 atlthe end'of 011e Cycle of Oscillation Of given in connection with the accompanying drawings, in the resonant circuit the trigger pulse will have reached which the grid of gas tube 2 which thereupon becomes conduc- Fig. l shows a high frequency pulse generating circuit in Uve Permittlhg Condenser 7 t0 discharge thrOugh the priaccordanoo with invention employing ve gaseous dis mary of transformer 11 with the result that a second pulse charge tubes; of energy is applied to the resonant circuit 32-30. Similarly, at the end of the second cycle of oscillation of the resonant circuit the trigger pulse will have reached tube 3 and so on until the remaining. condensers 8, 9 and 10 have been discharged through the primary of transformer 11. The resulting high frequency pulses produced at the output terminals 29 are shown in Fig. 2b, the trigger pulses 31 being shown on an expanded time scale at (a). The number of oscillations of tuned circuit 32-30 that lwill be produced by each pulse of energy applied thereto depends on the amount of damping present. In cases 0 where more than one cycle of oscillation results from the shock excitation of the circuit it will be evident that the first cycle of each oscillation will be reinforced by the frequency energy composing each pulse is determined prinsecon@ cyle of he preceding oscillation t.he Second cycle cipally by the number of tubes used. The invention, 5 of Osc1-uanon-wlu. be remford by the thlrd cycle of the therefore, is not limited to the number of tubes shown, by preceding oscillation and so on The high frequency pulse Fig. 2 shows the time relationship between triggering 50 pulse and generated high frequency pulses; and

Fig. 3 shows an alternative method of operating the circuit of Fig. l in which the sequence of gaseous discharge tubes are utilized more than once in the generation of a high frequency pulse.

Referring to Fig. 1, the circuit shown operates to generate a series of pulses of high frequency energy. The circuit employs tive gaseous discharge devices, such as thyratron tubes, numbered 1 through 5. The number of gaseous discharge devices needed depends principally upon the desired frequency of the generated wave and the desired pulse width, since the number of cycles of high way of example, in Fig. 1. representations of Fig. 2b are based on the use of the cir- The tubes 1 through 5 are connected in series with concult Shown in Fig- 1 and a degree 0f damping that results denser-s 6 through 10, respectively, aol-oss the primary in three cycles of oscillation for each shock excitation of winding of transformer 11 so that each condenser may disthe resonant eieuit- Sillee 011e gaseOuS tube is used t0 charge through the primary winding when the correspondgenerate each damped oscillation the number of cycles in ing tube is in a conductive state. When the tubes are in the high frequency pulse is determined primarily by the number of tubes used in the sequence, and secondarily by the number of cycles contained in each damped oscillation.

It is, of course, not essential that the time spacing between pulses 31 be uniform as shown in Figs. 1 and 2. This spacing may be varied in any desired way, however, in cases where a complete high frequency pulse is to be generated for each trigger pulse the spacing between trigger pulses should not be less than the duration of the high frequency pulse envelope. Also the interval between pulses must not be less than the deionization time of the gaseous tubes used.

In case where the high frequency pulse envelope duration desired is greater than the deionization time of the gaseoustubes used the sequence may be used more than once during each output pulse. This may be accomplished by the use of an accurately time-spaced multiple trigger pulse train such, for example, as shown in Fig. 3a. The resulting high frequency pulses, for a five tube sequence such as shown in Fig. l, are shown in Fig. 3b. The interval t between pairs ofktrigger pulses must be exactly equal to the period of the high frequency multiplied by the number of tubes in the sequence. Although Fig. 3 shows the trigger pulses in groups of two and three it is of course possible to employ any desired number of pulses in a group. It will also be evident from the above that a continuous high frequency wave could be generated by la continuous train of trigger pulses separated by intervals t.

The invention may be used for the broadcast of speech, music and similar intelligence by frequency modulation of lthetriggering pulses or amplitude modulation of the high frequency output energy.

We claim:

Apparatus for generating high frequency energy, said apparatus comprising a resonant circuit tuned to the desired frequency of said energy, coupling means for applying pulses of energy to said resonant circuit, said coupling means having a pair of input terminals, a plurality of gaseous discharge tubes each having at least an anode, a cathode and a control grid, a plurality of branch circuits connected in parallel across said input terminals, each of said branch circuits comprising a condenser and the anodecathode path of one of said tubes connected in series, means for charging said condensers to a predetermined potential, a grid circuit connected between the grid and cathode of each of said tubes, means forming part of said grid circuits for biasing the grids of said tubes sufficiently to render said tubes normally nonconductive at the said predetermined potential to which said condensers are charged, means coupling said grid circuits in cascade, said means comprising delay networks, each producing a delay equal to the period of the frequency to which said resonant circuit is tuned, connected between adjacent pairs of the grid circuits in said cascade, means for applying a positive trigger pulse to the first of the grid circuits in said cascade, and means for coupling said resonant circuit to a load circuit.

References Cited in the tile of this patent UNITED STATES PATENTS Chambers Oct. 13, 1953 

